The vast majority of homeowners in the area devastated by Hurricane Harvey lack flood insurance, leaving many who escaped the storm with little financial help to rebuild their homes and lives.

“I wish I had flood insurance now,” lamented Leroy Moore, a 58-year-old whose home in Northeast Houston filled with water. He cancelled his flood policy when it grew too expensive. He and his wife were rescued from the rising waters on Sunday by National Guard troops and are now sleeping in a church. “When it's a choice to make between things and life, sometimes you've just got to let the things go and hang on to life.”

Regular home insurance covers wind damage but not flooding. Homeowners have to purchase separate flood insurance policies from the government-run National Flood Insurance Program, which will end in late September unless Congress renews it. In Texas, the average cost for a NFIP plan is $500 a year, but it can rise to more than $2,000 for homes inside a floodplain.

Only 17 percent of homeowners in the eight counties most directly affected by Harvey have flood insurance policies, according to a Washington Post analysis of Federal Emergency Management Agency data. When disaster hits, the policies cover up to $250,000 in rebuilding costs and $100,000 to replace personal belongings such as TVs and furniture.

Everyone else who loses their home to flooding will be dependent on private charity and government aid, especially grants from Federal Emergency Management Agency.

But FEMA's help is a poor substitute for flood insurance: The grants, intended to help residents rebuild homes and cover hotel stays until permanent housing is available, are capped at $33,300. Most receive significantly less. Funds will be even tighter if Congress doesn't provide additional emergency funding for Texas soon.

To get a grant, “FEMA has to believe your house is damaged so substantially that there’s no area in your house you can live in,” says Saundra Brown, a lawyer whose home in Houston was flooded. She spoke to The Washington Post while removing drywall to prevent mold. Her advice is to take photos of everything.

President Trump vowed “very rapid action” to help victims, but aid is usually slow to arrive, particularly in a large-scale disaster that strains FEMA's capacity to inspect and assess all the damaged homes.

Brown has seen firsthand just how long FEMA can take. She heads up Lone Star Legal Aid's disaster response unit, a group of lawyersthat assists low-income clients, including helping them to get FEMA money. Some of her clients were fighting with FEMA for months after the smaller storms that deluged Houston with rain in 2015 and 2016.

“It’s not like the government comes in with big buckets of cash and just hands it out,” says Robert Meyer, a professor and co-director of the University of Pennsylvania's Risk Management Center, which studies natural disaster response. “People who don't have insurance may have to abandon their homes.”

Moore and his wife were sitting in the First Baptist Church in North Houston trying to comprehend how quickly everything they worked for was ruined by a horrendous storm. The couple fled the home they'd owned for 32 years with just the clothes on their backs.

Moore, a forklift driver, used to buy flood insurance from the government when it cost $200 a year, but he says the premium rose above $300, so he stopped. His home had never flooded before Harvey until now.

“I've been in Houston all my life … I've never seen it like this,” Moore said, looking around the room at so many other families in the same situation.

Losing a home without insurance compensation is financially devastating. A home is the most valuable financial asset that many middle-class Americans have. The median home value in Harris County, where Houston is located, is $138,000, according to the U.S. Census. A total loss could delay retirement or force people into bankruptcy. Even if they can rebuild, it's unlikely the home will be worth as much if it is now marked as prone to flooding.

Legally, homeowners in places that FEMA designates as “high-risk” flood areas are supposed to have the insurance, but the rule isn't tightly enforced. Across the country, only 12 percent of homeowners have flood insurance, according to the Insurance Information Institute. The rate is a bit higher in Texas, Louisiana and Florida, but even in those coastal areas, only about 20 percent get it.

“We’ve been arguing for a long time that more people should be purchasing flood insurance, but it’s a difficult product to convince people to buy,” says Tom Santos, vice president of federal affairs for the American Insurance Association.

Part of the problem is the vast majority of people hit by Harvey weren't even in a high-risk flood zone, says Chuck Watson, founder of Enki Holdings, which has estimated storm damages for years. Harvey is an unusual storm because it's triggering so much additional flooding as levees, dams and reservoirs overflow. “It's blowing up our usual models,” Watson says.

Private insurers largely avoid offering flood insurance because it's hard to price the risk and they lose money.The federal program is struggling financially.The NFIP is $25 billion in debt after paying out damages for hurricanes Katrina and Sandy. It will probably have to borrow more money to pay for Harvey, which is on track to be one of the most destructive in U.S. history. The NFIP is only authorized to borrow up to about $30 billion, meaning the agency could hit its limit after all the Harvey claims come in.

Congress would have to approve additional borrowing. That's on top of reauthorizing the program by Sept. 30. If NFIP's charter lapses, it would mean no new flood insurance policies could be issued and that there could be delays in processing claims from Harvey.

Even with federal help, Texas's Gulf Coastfaces a long, painful recovery. Current estimates are $40 billion in damages, which would put it behind only three other hurricanes: Andrew, which was a $48 billion hit to Florida in 1992, Sandy, which caused $70 billion in damages to the Atlantic Coast in 2012, and Katrina, which 12 years ago this week killed more than a thousand people in and around New Orleans and caused $160 billion in damage.

The best hope for those who don't get much FEMA aid is a low-interest government loan.“The largest vehicle for disaster recovery isn’t FEMA grants; it’s Small Business Administration disaster loans,” says Brown. Some businesses and charities in the Houston area are already offering aid and cheap loans up to about $10,000.

“Nothing like this has happened before in Houston. Individuals and businesses are all trying to help,” says Yuvette Chou, a 41-year-old who didn't have flood insurance and was trying to stay positive. She spent Sunday sitting with her husband on the stairs watching water seep into their home for the first time ever. Her employerhas already reached out to offer a low-cost loan. “I've learned my lesson.”

Houston, with 2.3 million residents, is America's fourth-largest city. It's the country's energy hub, and it has thrived thanks to the shale gas boom. In total, nearly 6 million people live in the eight counties most affected by the storm. One of the biggest concerns for the economy is whether people will leave after Harvey. Katrina demonstrated what such a storm can do to a major American city. New Orleans lost half its population in the year after Katrina struck. While some eventually returned, the city still isn't back to where it was.

Houston's middle-class homeowners are unlikely to have the savings or insurance to rebuild, and that could have devastating consequences for years to come. Ten years after Katrina, New Orleans residents who had their homes inundated with water still struggled to pay some bills and had lower rates of homeownership than those whose homes never flooded, according to a study by the New York Federal Reserve.

There's still a long road ahead, even for homeowners who have flood insurance. Finding people to do the repair work will be extremely difficult. Construction companies were already complaining they didn't have enough workers before the storm hit.

“I truly never thought this could happen,” says John Zepeda, a 34-year-old father who woke up at 6 a.m. Sunday to the sound of his two dogs barking feverishly. Water was seeping into the living room of his home in the suburbs of Houston. By noon, the water was waist deep.

Zepeda and a neighbor found a kayak and spent the rest of the day hauling people and pets to safety in their Willow Creek neighborhood. They were able to save a woman who was eight months pregnant. On their final trip, the water was rushing so violently that a rescue helicopter hovered overhead to ensure they made it to safety.

Zepeda's home and belongings, including a new truck in the garage, are ruined. Yet Zepeda knows he's one of the lucky ones. His wife Stephanie insisted they buy flood insurance after the massive Memorial Day flood in Houston in 2015. The water didn't touch their house that year, but seeing it come up the street scared them. He thought it was a waste of money, but she was adamant.

“Thank God we did it,” he said in a phone call from a relative's home.

Heather LongHeather Long is an economics correspondent. Before joining The Washington Post, she was a senior economics reporter at CNN and a columnist and deputy editor at the Patriot-News in Harrisburg, Pa. She also worked at an investment firm in London. Follow